Means for preventing unauthorized viewing of a surface



W. C. AND E. E. STRAUSS.

MEANS FOR PREVENTING UNAUTHORIZED VIEWING OF A SURFACE.

APPLICATION FILED JULY 9.1921.

354355,992, mmm Non 211, w22.- f 4H 70 C? M im JWMS' C. STRAUSFS .AND EDTTBD STRASS, OF CHICAS-0, LLENOIS.

TIENS FQRPREVENTING- UNUTHORIZED VIElIN'G OF A SURFACE.

Application filed July 9, 1921. Serial No. 483,591.

it known that we, d iiii'iiin C. S'rimnss and RDW/inn E. S'riniuss? citizens oi the United States, bothresiding at Chicago, in the county of Cook and State cil illinois, have invented a certain new and useful ini provenient in iiieans for Preventing TUnauthorized VViewing orav Surface, of which tiie'tollowing is a hill, clear, concise, land exict description, reference being had to the accompanying drawings, forining a part of this specication. y

@ur invention relates to ineans for pref venting unauthorized viewing ot a surface, and more particularly to a blinder arrangeinent for preventing the theft of the coinbination oi locks or" the permutation or conibination type, suchk as are coinnionlyeniployed in connection with safes, vaults, and the like. Y

it is a familiar 'fact that the combinations oit such locks are subject to theft by unauthorized viewing oi the successive refristrations of the markings by means of which the lock is opened. For example, it has heretofore been a siinpie niattei where such a lock is opened in the presence of other persons, for any of such persons to take down the combination troni a point reinoved from the operators position, and thereafter gain unauthorized access to the sate or vault as the case may be.

Our invention aims to provide a novel, y

simple and inexpensive blinder arrange nient, which will without materially impairing or interfering with the operators vision oi tiieinarkings in opening` the lock, eiiectively prevent unauthorized viewing or' the combination markings or indicia as they are moved into successive registration with the usualfiixed markings to open the lock.

in accordance with the teachings of our invention, a plurality ot' outstanding blindeis or grids are arranged across the surface unauthorized .'iewing oit which it is desired to prevent. VThese biinders or grids extend out such a distance and are so spaced that the angie ci vision byi means of which a view of the surface may be had, is possible only from the position occupied by the operator in opening the lock. The markings or indicia about the dial of the lock are preferably covered by a suitable shield having a viewing opening across which the outstanding biinders oi' grids extend.

iliiiiile our invention is particularly adapt` scope of our invention, we shall now de- Slbea specific enibodiinent oi the invention in connection with the accompanying drawings, inwhich:

Figure l is a front elevational. view of the dial ora lock with a shield and a blinder arrangement en'ibodying our invention in place thereover;

`Figure 2 is a top pian view of the saine;

Figure 3 is a side elevational view; .Figure 4 is a fragmentary vertical sectional view throughthe shield and blinder arrangement along the line 4--4 of Figure l showing the dial of the lock in elevation; and

Figure 5 is a fragmentary horizontal sectional View taken substantially on the line 5%5 of Figure l.

kiVith reference now to the drawings, 5 designates the usual operating spindle for unlocking the lock. This spindle 5 carries a disk or dial 6 having a system of markings and numbers arranged about the riin thereofi as shown at 7, and is provided at its outer end with a knob or iinger piece S. The knob or iinger piece 8 provides for turning the disk or dial 6 relative a surface 9 ,circuinscribing the periphery thereof to inove certain oi the markings 7 (depending upon the combination of the lock) into registra tion with a niark i() on the surface 9 to release the locking mechanism and leave the bolt ofthe lock free to inove as is well understood in the art.

A shield in the nature oi a dished ring ll mounted upon the surface 9 covers the markings and ninnbers T arranged about the rim of the dial 6, and it is behind this shield il that the di ai 6 is turned through that combination. system by whichthe lock is'opened. To facilitate mounting of the shield v1l, the surface 9 is in the present instance, provided with an annular shoulder l2 for receiving the outer edge of the shield. inwardly projecting pin 13 carried by the shield il is insertable into a cooperating opening the Suriace 9 t@ pOStion and maintain the vproper positioning of the lllhile, of course, not especially necessary,

shield thereupon. rhe shield 11 may be secured by a screw 1l or any other suitable fastening means to the dial 9 or surrounding surface as desired. The particular formation and mounting of the shield may of course bc varied. in arcuate opening 15 through the shield 11 forms a viewing opening through which the successive registrations of the markings 7 with the marking 10 are viewed by the operator in opening the lock. Y

rilhe blinder arrangement of our invention in the particular instance shown is in the nature of a casting 1G secured over the viewing opening 15 by means of a pair of suitable screws 1'?, the heads of which engage in the shield or cover ring 11. he cast-ing 1 6 comprises an upper marginal portion 18 extending along the upper edge of the arcuate opening 15, a lower marginal portion 19 eX- tending along` the lower edge of such opening, and a. plurality of substantially parallel outstanding blinders or grids 2O extending across the opening 15. The blinders or grids 20 may be partially encased if so desired. iillhile in the particular embodiment shown, the blinder arrangei'nent is in the nature of a separate piece 1G secured. to the shield 11, the blinder-s may be formed integral with the shield or otherwise desired. Where the piece 16 is cast, the inner edges of the blinders or grids 2O are preferably tapered to ay knife edge, as shown at 21, so that their thickness will not materially interfere with the operators view of the markings. However, the blinders or grids 20 may be in the nature of sheet metal leaves suitably secured in place, in which event such tapering of the inner edges would not be necessary. le do not of course, intend to limit the invention to the particular arrangement of the blinders 2O shown. ranged otherwise than vertically across the surface 9 and need not necessarily extend in parallel relation.

In either event, it will now be apparent that while the operator from his position A (Fig. 5) is afforded a perfect vision,not only of the marli'ings 7 iu'imediately adjacent the marking 10, but of a suliiciei'it number of markings i' to either side of the marking- 10 so that he will be apprised at all times of the particular marking moving into and out of register with the `marking 10 before registration is had. Substantially all lines rof vision from positions, such B other than that of the operator as for example to eitherI side of him, are screened from the dial 6 by the outstanding blinders, grids or leaves 20.

These blinders may be ar-l the opposite surfaces of the blinders 20 are preferably so finished that there will be no appreciable reflection of the markings on the dial G and the surface 9 therethrough.

Frequently, thedial of the lock is so positioned that the openingfor viewing the same is either above or below the direct horizontal line of vision from the operator standing` in front of the lock. To afford the operator proper vision in such event, the inner faces of the marginal. portions 1S and 19 of the piece 16 are finished at an angle as shown in Figure 1.

lVe claim:

1. ln combination, a surface to be viewed, a blinderarrangement for said surface, said blinde arrangement comprising a plurality of substantially parallel leaves arranged across the surface and projecting therefrom, the projection and spacing of said leaves bein such that unauthorized vision is screened from the surface thereby.

2. In combination, a lock having an. indicia bearing surface, a shield adapted for covering said indicia bearing surface of the lock, said shield having a. viewing opening and blinder means arranged across said viewing opening for screening out unauthorized vision therethrough.

The combination with a surface havingan area exposed to view of blinder means arranged across the exposed area of said surface for screening` out unauthorized vision of said area.

4. ln a blinder of the class described, an opening defining member, a. plurality of substantially .parallel blinder leaves arranged across the opening defined by said. member to prevent unauthorized vision there through, the inner edges of said leaves beingr relatively thin so as to not interfere with authorized vision through said opening.

5. ln. combination, a surface to be viewed, a member having an opening arranged to permit viewing of said surface therethrough, and blinder means arranged across and dividing said opening to prevent unauthorized viewing of said surface therethrough.

6. ln combination, a surface to be viewed, a member' having an opening varranged to permit viewing of said surface therethrough, and a plurality of blinders arranged across and dividing said opening to prevent unauthorized viewing of said surface therethrough.

ln witness whereof, we hereunto subscribe our names this 26th day of lilay. 1921.

W ALTER- C. STRAU EDVARD E. STRASS. 

